Is it acceptable to spend eight years encouraging people to do something, then stage a U-turn and tax them for following your suggestion?

Islington Council thinks it is. After encouraging residents to buy diesel cars since 2007 with its emission-based residents parking permit system, it has now whacked them with an extra £96-a-year charge for doing what it wanted.

This will at least double the cost of parking outside their house for many diesel car owners and is the equivalent of Islington hiking its council tax by 10%.

The council has called it a diesel surcharge, but let’s be honest it’s a diesel tax.

I should declare my hand here. I am an Islington resident and I have a diesel car, yet my objection to this runs far deeper than personal interest.

This is a tax that is deeply regressive. Not only does it hit lower income residents harder, but they are also far less likely to be able to afford to go out and buy a different car to avoid it.

Islington says this is needed to encourage people away from polluting cars – and that while diesel cars score better on CO2, they are more harmful for other pollutants. Yet the council itself wanted people to buy those very diesel cars.

Islington’s justification conveniently ignores how a similar effect could have been achieved by cutting existing parking permit charges to make petrol cars cheaper.

There’s certainly room to, as these are a colossal rip-off. The most recent publicised figures reveal Islington made a profit of £6.7m from parking and traffic fines in 2012/13.

To tell someone to do something and then suddenly tax them extra for it is wrong. Islington’s leaders should be deeply embarrassed.

With behaviour like this, is it any wonder people have so little faith in their councils?